Silk – fibre, biopolymer, biomaterial

More than a mere textile fibre, silk is a biopolymer and biomaterial composed of two protein molecules, fibroin and sericin.
Biopolymers can be derived from microbial systems and higher organisms like plants, or chemically synthesized from materials of biological origin. Medical, cosmetic, food and textile uses are common, while biosensor and even data storage usages are more recent. Their most important property is biocompatibility.
Biomaterials are non-living materials used in medical devices that interact with a biological system. In other words, materials used in contact with living tissues, blood, cells, proteins and any other living substance.

Polysaccharides: (plant/algae) starch (amylose/amylopectin), cellulose, agar,  alginates, carrageenans, pectins, gums (guar), konjac
Proteins: silk, collagen, gelatine, elastin, soya, zein, gluten, casein, albumin
Polysaccharides: (animal) chitin/chitosan, hyaluronic acid
Polysaccharides: (bacteria) xanthan, dextran, gellan gum, levan gum
Polyphenols: lignin, tannin, humic acid
Polysaccharides: (fungi) pullulan, elsinan, yeast glucans